1. Field of the Invention
The present invention relates to reagent preparing devices and specimen processing systems, and in particular, to a reagent preparing device capable of preparing a reagent from a plurality of different liquids, and a specimen processing system.
2. Description of the Related Art
Conventionally, a reagent preparing device capable of preparing a reagent from a plurality of different liquids is known (see e.g., U.S. Pat. No. 5,800,056). In U.S. Pat. No. 5,800,056, the reagent used in a measurement section is automatically prepared from high concentration reagent and pure water. The reagent preparing device described in U.S. Pat. No. 5,800,056 includes a reagent quantifying tank for accommodating a high concentration reagent, and a pure water quantifying tank for accommodating pure water. The reagent preparing device further includes a preparing tank, connected to the reagent quantifying tank and the pure water quantifying tank, for preparing the reagent inside, a storage tank, connected to the preparing tank, for accommodating the reagent prepared in the preparing tank, and a supply tank, connected to the storage tank, for accommodating the reagent waiting to be supplied to the measurement section. In U.S. Pat. No. 5,800,056, a concentration sensor including an electrical conductivity meter is arranged in the preparing tank, and the preparation of the reagent is completed assuming the reagent of the desired concentration is obtained when the electrical conductivity of the reagent is within a desired range.
The reagent prepared by the reagent preparing device described in U.S. Pat. No. 5,800,056 is used to measure the specimen in the measurement section including a flow cytometer. The flow cytometer is calibrated using a standard liquid described in U.S. Pat. No. 5,888,823 and the like so as to obtain an accurate measurement value.
However, even if the measurement section is appropriately calibrated, an accurate measurement value may not be obtained in the measurement section if the quality of the reagent supplied from the reagent preparing device to the measurement section is lowered. For instance, in the reagent preparing device described in U.S. Pat. No. 5,800,056, the reagent is supplied to the measurement section only when confirmed that a desired concentration is obtained by the concentration sensor, and thus the concentration of the reagent to be supplied is normally constant. However, if the electrical conductivity output by the electrical conductivity meter is deviated from the true value, the reagent of low quality having a concentration different from the desired concentration may be supplied to the measurement section although the reagent of the desired concentration is actually not obtained. The analysis result of the specimen measured using such reagent of low quality has low reliability, and a need to replace the reagent and perform the measurement again arises.